This invention relates to the purification of waste water which is high in carbohydrates including starch and at the same time enables obtaining from this high carbohydrate water a harvest of single-celled protein which can be used to feed chickens and other animals. Thus, the cost of the necessary purification is at least partially recovered in the ability to sell the harvest.
The invention is particularly useful in the processing of waste from potatoes and other high starch products as well as from products high in sugar.
For example, in the potato processing industry heretofore the waste treatment plants have been simple adaptations of municipal waste treatment techniques. The direct applications of aerated lagoons and other conventional treatment systems has resulted in major difficulties from anaerobic conditions and also the problem of the solids bulking in final clarifiers. There has been a great deal of public pressure on the regulatory agencies to overcome the pollution which is met when the waste is simply dumped into the rivers and streams or left in these lagoons to develop a smelly and objectionable product while undergoing such purification as is there undergone.
In the present invention a fully aerobic system operates in quite a short time to convert the non-sterile starch, sugar, and other wastes into single-celled protein organisms which can thereupon be separated from the effluent, as by centrifuging, so that the effluent itself has been sufficiently purified for unobjectionable feeding into streams and the like, while the single-celled protein material can be largely harvested, dried, and used to feed chickens and other such animals.